On blogspot, press "new post". Next to it at the top it'll say "new post" "edit posts" "edit pages" (or maybe "new pages") Click the page tab and create a new one, just enter a title. There should automatically be the "pages" gadget added to your blog which automatically lists any pages you've created. This can be managed by going to "Design" and editing the appropriate gadget.
As for allowing people to add links to their shop, I've seen this used:
http://www.inlinkz.com/?refId=12320I don't know how to install it because I've never looked into it, but it allows visitors to add their links to your page.
I will say this though: I created a blog to promote my shop, and it didn't work. The only way that it will work is if you only mention your shop occasionally, because people will not be interested if you only post about your shop. I decided to turn the blog into a more craft-based site, and I post printables/tutorials/recipes once a week, usually a friday, and I feature members from Etsy, from both my team Etsian Ballyhoo, and things that I've added to my favourites that week.
I would suggest don't talk about your shop unless you want to mention that you have a sale going, and instead make sure you post the Mini Etsy at the top of your blog so that it can be clearly seen.
This is my blog (as you can see by the name it was initially for my shop, but I intend to change this soon to make it more stand-alone):
http://peachesandpebblesweekly.blogspot.comAs you can see, my mini etsy is right at the top and clearly seen, I've also added christmas shipping deadlines in an even clearer place (which is more important, and also lets people know that you have a shop straight away if they've just wandered in). I also try to make sure I post worth-while content for my followers. The best thing to do is to put the focus onto other members of Etsy - interview them, feature them, etc - and then give them the link once you've posted it. Most people (but not all) will then post a link to that page on their own blog, or their facebook, twitter, etc, which also draws in new traffic. These new people will see your etsy mini (I suggest having the max 5 thumbs - it'll help people get a real feel for your shop) and if they like what they see, they'll come over to your shop. If they don't, but they like your blog, they'll follow you, and the next time you mention a sale, they might be inclined to look again, and maybe buy.
That's the best advice I have for you on this specific subject. Good luck!